Westport Quadrangle, Leeds and Grenville Co., Ontario, Canada
|Latitude & Longitude (WGS84):||44° 32' 59'' North , 76° 19' 59'' West|
|Latitude & Longitude (decimal):||44.55, -76.3333333333|
First report of grandidierite in North America (together with the one at Gananoque area, Ontario). Grandidierite grains are up to 0.04 x 0.18 mm in size.
High-grade regionally metamorphic rocks; formation conditions: 675-800oC, ca. 4-6 kbar. Some minerals are present in gneiss, not in a direct contact with grandidierite.
5 valid minerals.
Rock Types Recorded
Select Rock List TypeAlphabetical List Tree Diagram
Entries shown in red are rocks recorded for this region.
This geological map and associated information on rock units at or nearby to the coordinates given for this locality is based on relatively small scale geological maps provided by various national Geological Surveys. This does not necessarily represent the complete geology at this locality but it gives a background for the region in which it is found.
Click on geological units on the map for more information. Click here to view full-screen map on Macrostrat.org
|Neoproterozoic - Mesoproterozoic|
541 - 1600 Ma
|Grenville Supergroup and Flinton Group|
Age: Proterozoic (541 - 1600 Ma)
Stratigraphic Name: Grenville Supergroup and Flinton Group
Comments: Grenville Province Central Metasedimentary Belt
Reference: Ontario Geological Survey. 1:250 000 scale bedrock geology of Ontario. ISBN 978-1-4435-5705-4. Miscellaneous Release–Data 126 - Revision 1. 
Grew, E.S. (1983) A grandidierite-sapphirine association from India. Mineralogical Magazine, vol. 47, n° 344, 401-403.